Overhead mounting for tubular lighting fixtures



Aug. 14, 1951 T. B. FARRINGTON ET AL OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES I 8 Sheets-Sheet 1 Filed April 25, 1945 mus/wens.

MAYER B. FARR/N6 ran! W40: 7? KELLER If/mama L. DALZELL 4 T TORNEYJ Aug. 14, 1951 T. B. FARRINGTON ET AL 2,564,328

OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES Filed April 25, 1945 s Sheets-Sheet 2 INVENTORJ.

Turn 8. flmnmcmn WAOE 7. KELLER HAROLD L. DALZELL g- 1951 T. B. FARRINGTON ET AL 2,564,328

OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES Filed April 25, 1945 8 Sheets-Sheet 5 T. B. FARRINGTON ET AL 2,564,328

OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES 8 Sheets-Sheet 4 Filed April 23, 1945 INVENTORJ- Farah B. A'Mnuvo ran Wan: 7. KELLER Hmaw L. DAL-ZELL Aug. 14, 1951 T. B. FARRINGTON ET AL OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES 8 Sheets-Sheet 6 Filed April 25, 1945 INVENTflRJ Farm 5. FARR/Nora WADE T. KELLER HARM-O L. 041.25 57'- /7a4 M ATTORNEYJ.

Aug. 14, 1951 T. B. FARRINGTON ET AL 2,564,328

OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES Filed April. 23, 1945 8 Sheets-Sheet '7 \J 7Zc 7/ 82 7 a 74- I l 8b 4 94' 6 8 9 9 85 INVENTOIhS.

7 T m Farm 5. fiRRuvaro/v -aI 77 W40: T. KELLER Hanna L. 041.25

' AM/ 1y 5- 4,10%.

Aug. 14, 1951 T. B. FARRINGTON ET AL 2,564,328

OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES Filed April 23, 1945 8 Sheets-Sheet 8 I I705 /7z :46 /7// E m 1 70 m9 M/vE/vToRJ. MAY R B. fimR/Mcnw WADE T KELLER HARam L. DALZELL Bx /7&M.44

Arron/vars.

Patented Aug. 14, 1951 UNITED STATES PATENT OFFICE OVERHEAD MOUNTING FOR TUBULAR LIGHTING FIXTURES Application April 23, 1945, Serial No. 589,822

' 3 Claims. (01. 248-320) This invention relates to improvements in disconnecting and lowering lamp-hanger structure. An object of the present invention is to provide an improvement in the combination of a fixed hanger member in an elevated position and a lowering hanger. member adapted to be raised and lowered therebeneath, said lowering member carrying a lamp. Our improvement provides power means for assisting at least the lamp hanger raising operation. In one form, the power means is aspring in which; energy is stored during the lowering operation, and in another form, thepower means is an electric motor.

.An object of the present invention is to provide an improvement in lightingfixtures wherein fixed electricalcontacts aremounted in anelevated position .a-ndsupplied withel'ectricity from asuitable source, and a lamp-supporting structure, arrangedto be raised and lowered with respect to the elevated fixture, is provided with electrical contacts adaptedto engage and coact with the fixed contacts sov as to energize the lamp when in its raised position. In the above combination, we provide the improvement of a spring-actuated counterbalancing device having flexible tension members .for supporting the lowering member from the elevatedfixed member, the tension members being so'connected with the spring-counterbalancing device :as toload the spring as the lamp fixture is lowered so that the weight of a relatively large fixture may be counterbalanced and theenergy of thespring may be utilized to assist return of the lamp fixture to its elevated position.

Our invention also provides a fixed trough-like memberadapted to be' secured in an elevated position either in one piece or a plurality ofpieces of sufficient length that a plurality of lowering lamp .hanger members may be. housed in the trough-likemember and-raised and lowered relative thereto. In such a device, each of the'lowering. members carries the electrical equipment for energization and control of the lamps in an exposed-arrangement, when lowered, for easy accessibility for maintenance, repair, and'repla'cement, all of these electrical parts being housed within the troughelike elevated fixturewhen the lamp supporting member is raised.

In apparatus like that described above, fixed electrical conductors may utilize the elevated trough-like'member asa wiring conduit, the 'vari-- ous sets of contacts being arranged in spaced relationship along the trough-like member, electrically connected with these conductors, and each set of contacts being adapted to energize the associated lowering lamp. hanger member.

Our invention is peculiarly adapted tothe support of tubular lamps of either the hot or cold cathode type. Such lamps are often of a dimension rendering them unwieldy. Also these lamps require ballast or transformer devices, starters for the lamps, and special tube sockets allof which may be mounted by our improved arrangement on the lowering member foreasy accessibility. Our invention also provides for the easy removal of the tubular lamps and elongated reflectors associated therewith so that these parts are readily disassembled from all electrical parts and may be readily washed by inexperienced help.

Certain features of our invention are not limited to lamps of the tubular type as will hereinafter appear.

The present invention provides novel means for insuring equalized engagement of a plurality of electrical contacts, part of which arefixed and part of which are connected with the lowering lamp-supporting member.

Our invention also provides novel means for removably latching the lowering member to the elevated member when the parts are in position for use.

Our invention also contemplates'the use of various spring actuated counterbalancing devices, some of which are peculiarly adapted for the mounting of lamps in a more elevated position than other of the embodiments as will appear from the description.

Still another object of the invention is'to provide means for locking a hanger member in lowered position during a servicing operation.

Other objects of the present invention include the specific arrangement of the various parts including the fixed elevated members, the frame of the lowering member and arrangement of parts thereon, the details of the connection and control of the flexible tension members which support the lowering hanger, the means for insuring proper registration of the fixed elevated member and the lowering lamp supporting member when they aremutually engaged in operating position, and other improvements in the various parts and functional relationship thereof as will more fully appear from the accompanying drawings anddescription.

In the drawings,

Fig. 1 is a perspective view showing a continuous trough-like member fixed in elevated position and adapted to coact with a plurality of lowering lamp hanger members;

Fig. 2 shows a single lamp hanger member associatedwith an elevated fixed member supported on drop stems from a ceiling or the like and illustrating the operation of lowering and raising the lamp-hanger member;

Fig. 3 is an exploded View of the device of Fig. 2 illustrating how the lamp-supporting member may be lowered and the reflector and tubular lamps separated therefrom;

Fig. 4 is a side elevational view of the device of Fig. 2 or one of the devices of Fig. 1 with the lamp hanger partly lowered;

Fig. 5 is a top plan view of a portion of the device of Fig. 4, this view being taken along the line 55 of Fig. 4;

Fig. 6 is a bottom plan view of a portion of the device of Fig. 4, this view being taken along the line 65 of Fig. 4;

Fig. 7 is an end elevational view of the device of Fig. 4;

Fig. 8 is an enlarged sectional view through an upper contact taken along the line 8-8 ofFig. 6; V Fig. 8a is an enlarged sectional view through a lower contact taken along the line 8a8a of Fig. 5;

Fig. 9 is a detail sectional view taken along the line 9--9 of Fig. 14;

Fig. 10 is a side elevational view similar to Fig. 4 but showing a modified form of our device;

Fig. 11 is a top plan view of a portion of Fig. 10 taken along the line of Fig. 10;

Fig. 12 is a bottom plan view of a portion of the device of Fig. 10, the same being taken along the line |2--|2 of Fig. 10;

Fig. 13 is a View taken along the line |3--|3 of Fig. 10;

Fig. 14 is an enlarged sectional view taken along the line |4| 4 of Fig. 11;

Fig. 15 is an enlarged transverse sectional view taken along the line |5| 5 of Fig. 11;

Fig. 16 is a top plan view enlarged of the central portion of Fig. 5 showing a modified form of contact mounting;

Fig. 1'7 is a side elevational view of the same taken from the position of line of Fig. 16;

Fig. 18 is an enlarged fragmental view like a central portion of Fig. 4 showing a side elevational view of a tape-clamping device; 7

Fig. 19 is an enlarged fragmental view like a portion of Fig. 5 showing a top plan view of the tape-clamping device.

As shown in Figs. 1 to '7, one form of our device contemplates the mounting of a downwardly opening trough-like device 2| adapted to house electrical conductors 22 for supplying energy to a pair of fixed electrical contacts 23 which engage the separable contacts 24 on a lowering lamp hanger member generally designated 25 which carries one or'more tubular lamps 26 and a reflector 21. A single such combination may be utilized as shown in Figs. 2 and 3, or a plurality of trough-like members 2| may be secured end to end as'indicated at 2| (Fig. 1), secured together by channel couplers 28. In such an arrangement, a plurality of lowering members 25 may be housed in the continuous member 2|, there being pairs of contacts 2324 for each of the devices 25', each of the pairs of contacts 23 being connected with conductors 22 which extend the entire length of the trough-like member 2|. It results from this construction that the member 2 serves the double purpose of housing the parts of the lamp hanger member when the latter is in elevated position and also as a wiring conduit for the electrical conductors 22'. With our improved arrangement it is possible to arrange a continuous member 2| along the length of an elevated ceiling as in a large store, assembly room, or the like with a plurality of individual fixtures 25', like those presently to be described, each fixture supporting lamps and reflectors and adapted to be individually lowered and serviced without the use of ladders, cumbersome loose cables, or the like. The only equipment needed for the lowering of the lamp hanger members is the stick 29 used by the operator.

In Fig. 1, we have shown the member 2 I which is suspended from a span Wire 30 but which may be attached directly to the ceiling structure as shown in certain other of the views or may be supported on a plurality of drop stems 3| provided all of the members 2 are supported at the same level and connected end to end to form a continuous trough or conduit.

Referring now more specifically to Figs. 3 to 7, we will describe one of the lowering lamp hanger members 25 and its cooperation with the fixed member 2|, but it should be understood that the members 25' and 2| of Fig. 1 are exactly like these except for the elimination of end walls at the point 28 of Fig. 1, and these specific differences will be pointed out later.

The member 2| which is mounted in a fixed elevated position comprises a downwardly opening trough-like structure of sheet material or the like and comprises a top wall 2|a through which the securing members pass for attaching the member 2| either directly'to the ceiling or to a span wire 30 or to drop stems 3| or other suit able mounting structure. Extending downwardly from the top wall 2|a are the parallel side walls 2|b which define the narrow upper portion of the trough. Below this are the shoulder walls 2|c extending laterally outwardly and connected with the depending side walls 2| d which define the lower and wider portion of the trough. The bottom edges of these walls 2|d may be provided with an inturned bead 2|e to give a finished appearance and to cooperate smoothly with the guiding portions of the lowering hanger member as will later appear. Mounted centrally in the upper narrower portion of the trough and se-' cured to the top wall 2|a by means not shown is channel-shaped base 32. The parallel side flanges 32a of this base extend downwardly and support between them a pair of straps 33 secured to the flanges by the screws 34. In the center of each of these straps is secured an insulator 35 of porcelain or the like to which is secured one of the contacts 23 which prefer-ably has a contact surface facing concavely downwardly. Each of the contacts is electrically connected with a binding post 23a to which is secured by solder or the like a conductor 36, and each of these con ductors is electrically connected to one of the supply conductors 22, previously mentioned, in a manner not shown and forming no part of the present invention. Between the straps 33, a strap 31 is provided also supported by the flanges 32a, and in the center of this strap is a slot 38 adapted to receive a latching device later described.

Means is provided for guiding the member 25 into alinement with the member 2|. For endwise alinement, this comprises a pair of wing members 39 secured to the fixture 2| and providing walls sloping downwardly and outwardly from thecenter of the fixture for coacting with portions: 40 of the lowering hanger member. For sidealinement plates 42 have portions 42!) bent to engage the sides of member 2| as the lowering: member is raised.

The lowering hanger member 25 consists of an amazes intermediate frame4lto which the lamps 26 and reflector 2'1 are detachably connected so that all of=the electrical and mechanical working parts are carried by the intermediate frame and readily accessible for maintenance and repairs when the hanger member is lowered, while the'lamps and reflector may beremoved and readily Washed without any danger of moisture reaching any electrical parts. By this arrangement, an unskilled worker can clean the lamps and reflectors without knowing anything about the care and maintenance of the electrical part of the equipment and withoutdanger of doing anything to impair the efficiency of the lighting equipment.

Theintermediate frame 4| comprises a' pair of elongated parallel rods or bars 4la' which extend substantially from end toend of apparatus supporting tubular type lamps such as that disclosed in Figs. 2 to 7. These rods are tied together at the ends by plates 42 welded or. otherwise rigidly secured to the under side of the rods. They are also tiedtogether by other members mounted thereon as will presently appear. With lamps of the tubular type shown at 26, a, ballast or transformer unit 43 is usually provided. This ballast is shown as supported on two straps. rigidly connected to the rods Ma, and the ballast is secured by screws or bolts to the straps 44. Starters are necessary for the lamps 26, and these are shown at 45 mounted on a plate 46 which in turn is rigidly connected to the rods 41a. The lamp Sockets 4! are connected to the plates 42 in the usual manner. It will be understood that the lamps 2% are removably secured in the sockets 41 in the usual manner. The electrical contacts 24 are connected by suitable wiring to the ballast 43, the starters 45, and the lamp sock' ets 4! in a usual and known manner which forms no part of the present invention. It is suflicient to state here that the current furnished at the contacts 24 is suitably changed to supply the lamps 26 and the current fed thereto through the sockets 4'5 with any known type of control equipment such as the starters 45.

Means is provided for counterbalancing the greater portion of the weight of the lowering hanger member 25 as the same is raised and lowered with reference to the fixture 21. This means takes the form of an energy-storing means 48 mounted on one of the members 2| or 25 and having flexible tension members such as the tapes 49 connected between the energy-storing means and the other part of the fixture so that as the hanger 'memberis lowered and raised, the energy-storing device is loaded and unloaded respectively. As shown in this form of my device, the energy-storing means 48 comprises a plurality of spring actuated sash balances of the general type shown in United States Patent 1,254,647, granted January 29, 1918, to William Bennett, or shown in United States Patent 2,051,412, granted August 18, 1936, to Edgar L. Gardner. It is sufficient to state here that each of the tapes 48 is wound about a drum 48a rotatably mounted on pivot 48b and urged by helical spring 480 in a direction to wind up the tapes 49 on the drum 48a as the hanger member '25 is raised.

The springs 480 have an initial tension tending to wind the tapes 49 on the drums 48a. and this tension is sufiicient to balance all but a few pounds of the total weight of the parts to be lowered. Then as thehanger member is lowered by the 'pull of the operator on the stick '29,

he springsr itlc are additionally loaded. "It results fromth'is construction, that when "the lowering hanger member isxfirst unlatched from the upperfixture, the partially unbalanced weight of the 'lower .member causes 'it to drop quickly a short distance giving a quick break between the mating el'ectricalrcontacts. The springs 480 then become loaded to the point where they fully balance the weight of the lowermember. .As the operator pulls the lower member. down to a servicing position, the springs are additionally loaded to storeenergyavailable later to return the lowering hanger member to a position adjacent the upper fixedmember, after which a slight final push serves to latch the lower member to the uppermember. v

Each .of ,the sash balances shown at 48 has .a horizontally extending ear 48d and a vertically extending ear 486 for attachment to the supporting structureabout to be described. The members previously designated at 4|! are the end members of a generally U-shape frame, the bottom of which lies between the rods Ala. This subframe. is secured tothe frame 4| by means 'of..angle members .50, each .welded to one of the. end walls of vthesubframe 40 and in turn boltedor welded to the rods 41a. Rigidlyfastened to the bottom wall of the .subframe 45 are bracket members 5| tohthe upper ends of which theears 48d are secured as by means of the screws52. The ears 48c are secured to thesubframe 4!).by means of the. bolts 53. The upper ends of the tapes .49 are secured to theelevated fixture channel member 32 as best seen in Fig. 4. Supporting means .forthecontacts 24 and the latch member-54 is provided by bracket .55 which is rigidly mounted between the .brackets5-I. vThe details of this portion of the device are more clearly shown in Figsal and 8a.

Referring now to Fig. 8a, in suitable openings in'the bracket 55.-are-mounted porcelain insulators .56 which are held invplace by'nuts 51. Suitably. mounted in the center of each-insulator is a vertically. positionedrod 58-to the upper end of which is securedone of the contacts 24. A helical springia59 is engaged between the contact 24 and the insulator 56 so as to yieldably hold each contact 24-inraisedposition. The wires for. energizingthe lamps -26 are connected'to the binding posts 60 whichare electrically connected through the .rods'58 with the contacts 24. Itresults from this contact construction that whenthe hanger-,me-mberis raised to operable position where thecontacts "24 engage the fixed contacts 23, equalization of pressure between the two pairs of contacts is assured becauseof the yieldable mounting of the contacts 24. ..-Between the contacts. 24 and located centrally of-the. entirelamp fixture is the latching device 54. As shownin Eig. 4, hollow sleeve 6! is mountedfor limited vertical .movement in the bracket memberand the subframe 40. Suitable collars limit the vertical movement of the sleeve. At its upperend, the sleeve carries the bayonet, joint latching end- 54 which in general conforms .to the shape ,of the slot 38 previously described but is adapted to pass through the slot.

The lower end .of the sleeve 6| is flared asshown at .6la, and just within the mouth of this flare an elongated verticalsloti 61b is provided in the wall ofthesleeve with a registering notch 64a in plate '64 which forms a' bottom portion of the bracket 55. "These are analogous to slot I 05b and notch 102a of Fig. 14. With this construction a rod 29;held in the'hands of an operator standmew ing on the floor, is inserted in the flared end 6Ia. The upper end of the rod carries a laterally extending pin (not shown) of a usual type which is engaged in the slot 6Ib and serves to rotate the sleeve 6| as the rod 29 is twisted. The operation of the latch should now be obvious. With the latch head 54 in registration with the slot 38, the hanger member 25 is raised until the head 54 has passed through slot 36 in plate 31 so that the head 54 is positioned above plate 31. Then rod 29 is turned so as to rotate sleeve BI and head 54 through a ninety-degree angle which positions the head 54 crosswise of the slot 38 and latches the lowering hanger member firmly in its upper or operative position.

The reflector 21 may be detachably connected to the frame 4| by any suitable means such as the wing bolts 66 shown in Figs. 3, 4, and 5 which pass through the upper wall of the reflector and carry at their upper ends a cross pin 66a which is adapted to pass through slot 42a in plate 42, after which a ninety-degree turn latches the wing bolts in position.

Another manner of mounting the contacts 24 which may be substituted for the structure shown in the central portion of Fig. 4 is shown in Figs. 16 and 17. The brackets 5| are like those previously described, but the cross bars 55' are fastened near the upper ends of brackets 5| so as to support the contact structure about to be described. The contacts themselves are each mounted in a porcelain block I63, and these insulator blocks are mounted on opposite ends of the oscillating bracket I64. This bracket has side ears I64a each having a vertical slot I64b therethrough. A screw I65 is fastened in each of the cross bars 55 to enter into the slots I64b, thus removably supporting the bracket I64 in oscillating position with limited vertical movement permitted. Opposite ends of the bracket I64 are bifurcated to provide arms I640 for slidingly receiving a groove in the insulators I63. Cotter pins I66 hold the insulators in the bracket I64. Means is provided for yieldingly urging the bracket I64 upwardly. In the present instance, this comprises a pair of parallel leaf springs I61 each of which has its central portion mounted on an L-shaped bracket I68 secured to the central portion of cross bars 55. In the usual manner, the electrical apparatus carried by the lowering hanger member is connected to the binding posts 24' which are electrically connected with the contacts 24. It results from this construction that pressure is equalized between the contacts 24 when they engage the mating contacts 23 on the upper fixture.

If desirable or necessary, means may be provided to hold the lowering hanger member 25 in is lowered position while servicing the same by means requiring little effort or attention on the part of the operator. As shown in Figs. 18 and 19, the tapes 4!! may be clamped to a fixed portion of the apparatus so that the springs 480 will be unable to wind the tapes on the drum 48a. A very simple manner of doing this is disclosed comprising a clamping bar I69 positioned on the side of tapes 49 opposite the upstanding ear of the bracket 40. Mounted on this bracket is a clamping lever IIfl connected by link III with the central portion of bar I69. The clamping lever has a cam surface IIila. adapted to bear against the bracket 40 and to pull the link III toward the right as viewed in Figs. 26 and 27 when the lever IIDb is moved approximately ninety degrees in a clockwise direction. -.The

flat surface IIllc will then hold the lever in this position against the tendency of spring II2 to release the clamp. The lever IIO rests on a small angle bracket I13 which is secured to the bracket 46. The operation of this clamping device should now be apparent. When the hanger member 25 is in the lowered position desired for servicing, the clamp IIII is moved from its normal released position shown in Fig. 19 to a position ninety degrees clockwise therefrom (Fig. 18) causing the bar I69 to hold the tapes 49 clamped against the bracket 46 immovably. The clamp is quickly released by the reverse movement of the handle I'Iflb when it is desired to return the hanger to its elevated position.

In Figs. 10 to 15, we have shown a modified form of our device wherein the various parts are of somewhat different character, but they fulfill the functions already described and provide the same basic combination. In this form of our device, we have shown the upper or elevated fixture ll of trough-like character as best seen in Fig. 12 and having the same general form as the fixture 2| previously described. In the center of this upper fixture is permanently secured the generally channel-like member I2 having a central web 12a, downwardly extending side flanges 12b, and laterally extending flanges I20 at the bottom of the side flanges. This member is wholly housed in the upper portion of the trough II as clearly seen in Fig. 13. The parts II and I2 may be mounted on drop stems 3| passing through the openings IE5, or bolts may be passed through these openings to secure the fixture to a ceiling structure so that the ceiling line occurs onthe level of the line A (Fig. 100, or the entire device may be recessed into the ceiling down to the lower edge of reflector 2! in what is known as a flush mounting. A junction-box mounting of the member II is shown in Fig. 10. A junction box 68 is mounted in the ceiling in the usual manner and has a stem 69 passing through the members II, I2, and I5 and secured thereto by a nut on the lower end of the stem. Wiring conduits ID, of a usual character, serve to lead the feed wires to the junction box and thence through the stem 69 to the interior of the member II. A pair of flxed contacts I4 are mounted on the channel member I2 and insulated therefrom by means similar to that already described in connection with Fig. 8a. These contacts have their binding posts 14a electrically connected with conductors 22 which extend through the trough-like fixture II as previously described and may run through a plurality of fixtures II placed end to end in a manner similar to that described in Fig. l. A latch plate I5 is secured to the channel member 12. This has a bottom plate 15a through which is cut the slot 152) to receive the latching head I6 carried by the lowering hanger member.

This lowering member as best seen in Figs. 10, 11 and 13 comprises an intermediate frame II' analogous to frame 4| previously described and separable lamps 26 and reflector 21 like those previously described. The frame 11 comprises two elongated parallel side frame members IIa extending substantially the full length of the device, but in the present instance these are channel-shape members with their flanges facing inwardly as best seen in Fig. 13. The side frame members are rigidly connected together at the ends by plates I6 upon which are mounted the tube sockets 41 as before. These plates also have slots 18a for receiving the heads 66a of the wing bolts 66 which detachably secure the reflector 21 to the frame-'11; the-sameasdescribed in connec tion with the first form of my'device.v Strapslll are rigidly secured acrossthe top fiangesoi the members Hot and support the ballast-88which serves in the energization-of the lamps 28. In the center of the frame 11, the plate 81 is rigidly connected between the frame members Ila andserves to mount certain of the parts later described.

Means is provided for counterbalancing the weight of the parts to belowered which in function is similar to thatpreviously described. However, in the form here-shown, a means is provided for winding and unwinding a muchlo-ngerlength of the flexible tension supports upon which thev lowering hanger member ishung. This present.

device is of the shade-roller typeand comprises one or more (two being shown) elongated cylln drical drums 82 and 82', each rotatablymounted on a shaft like 83 and 83 respectively, which ex tends out opposite ends of drums 82 and 82, and

both shafts are supported by bracket meansr At the right-hand end, as viewed in Fig. 11, an I shape bracket 88 is rigidly connected between the frame members 71a, and its upstanding flange 84-11 has an elongated: slot 841) for receiving the flattened end of one of. the shaf'ts 83. The bracket also has an opening 840 to'recei-ve the end of the other shaft 83". Likewise. at the opposite end, a bracket 85 is rigidly connected across the side frame members Tia and. has an upstanding flange having a slotted opening (not shown) exactly like 8% to receive the flattened.

left end of shaft 83. as viewed in Fig. 1 1. The left end of shaft 83 is mounted inan opening similar to- 840 previously described. Inside of the drums 82 and 82 are elongated helical springs 88, each surrounding its associated shaft and having the left end of the spring securedto shaft 83 or 83 as the case may be and the right-hand end of the spring secured at 8! to drums 82 and 82', respectively (all parts as viewed: in Fig. 11:). l'he lefthand end of each spring 88 passes. through an elongated slot 88a in the associated shaft'to per.- mit spring elongation under torsion;

Spaced on drum 82 are thecable spools 88, and

in like manner spools 88 are mounted ondrum.

82'. These spools may berigid-ly connectedzto their associated drums in any-desirable manner although a special mounting will be later de scribed. Each of the spools is grooved as shown to receive one of the cables 89. Each orthese cables has an end fastened to the fixed'upper channel member 12 by means-of; thepins 98'Which pass through the flanges 12b. The arrarigement of the cables on the spoolsi88 and the direction of rotation of the drums 82, 82- with respect to their associated springs issuch that all. of the cables are wound and unwound inunison respec tively as the lowering hanger member is raised or lowered.

The springs 86 both have an initial tension tending to wind the cables 89 and the spools 88 and 88' and adapted to balance all but a few pounds of the total weight of the parts to be lowered. The relation between the springs 86, the spools 88, 88', and the cables 89 is such that the springs are additionally loaded as the hanger member is lowered. It results from this construction, as in the first-described modification, that when the lowering hanger member is first unlatched from the upper fixture, the slight unbalanced weight of the lower member causes it to drop quickly a short distance giving a quick break between the mating electrical conis necessary to latch the hanger member to" the upper fixed member. I I

Anspecial mounting means for spools 88 and. 88 on the drums 82, 82' is shown in Fig.- 15; and thisisuseful where there is a slight difference in. the/length of the cables 89 either inoriginal assembly or due to uneven stretching of the cables.- In this improvement, key'9-l ls provided rigid. with the drum 82, and a plurality of. key-'- ways 92 are provided on the inner face: of the spool 88. l he-key 9| may then beplaeed in-one of the keyways 92 so chosen as to-give the adjustment necessary to the associated cable 89.-

Special means may be provided: for aidingin: the wind-ingot the cables 89 on their associated spools and to provide against backlash or loose. portions of the cable interfering with the regular. winding. on the spools. This improvement is clearly shown in Figs. 1-1- and 1 5 wherein-a plate 93 is fixed to bracket Bla mounted on platefll,v

and binge plates 94 parallel to the cable-receivi-ng surfaces of the spools 88, 88' are connected tothe bottom plate by means of the hinge pins 95.- Where there are two parallel spools'as shown in: Fig. 11,- we prefer to mount the-plates 84 in parallel opposed relationship and utilize a single helical compression spring 96 between the plates- 94 so as to urge each plate toward its associated spool. The spring 98 is held in place by the studs Mo on the plates 94. It results" from this construction that each cable 89 is causedto fol--' low a spiral groove in its associated winding drum in a regular and even manner.

Electrical contacts 97 are mounted on the loweringhanger member in position to engage and. coact with" the fixed contacts 14; Means isprovided for equalizing the pressure engagement of the two pairs of contacts, and while this functions the same as the means described in con-'- nection with the first modification, it is of a somewhat diilerent construction. The contacts 91 are each mounted inaninsulating porcelain 98,. and these are carriedin bifurcated arms 99a of a. bracket 99 being held in place by cotterpins [98 The bracket 99 has a sleeve portion- 98b which slidably engages over anenlarged portion |8la of. stem IUI, the lower end of which is clamped on the plate 8| by means of the flange IiHb; overlying the plate, and the nut I82 threaded onthe lower end of the stem beneath the plate; A helical spring I83 surrounds the upper portion of stem I01 and is engaged between the flange 990 of the bracket and the portion l8 la of the stem so as to yieldingly urge the bracket 99 toward its uppermost position. A flange Ifllc limits the upward movement of the bracket. It results from this construction that the bifurcated arms 99a of the bracket may rock on the central mounting so as to provide an equalization of contact between the two pairs of upper and lower contacts 14, 91. The wires (not shown) for energizing the lamps 28 are suitably connected in a known manner between the contacts 91 and the tube sockets 47 including the proper connections to the ballast 88 and the lamp starters I04. These connections are 11 well known in this art and would only serve to confuse the present drawings.

The latching head 16 is rigidly mounted on the upper end of a stem I which is mounted for limited vertical sliding movement inside of the stem Ill]. The lower end of the stem is flared as shown at l05a. Near the bottom of the stem one of the walls has an elongated slot therethrough as shown at 105b, and opposite this slot is a small notch [02a in the nut I02. In operating the latching device, the operator places the upper end of a pole 29, like that shown in Fig. 2, inside the stem I05 with a small laterally extending button on the rod 29' inserted through slot i951) and notch 12a to a position above the lower wall of nut I02, after which the rod 29 is twisted so as to turn the latch 16 ninety degrees to unlatch it. The hanger member is then lowered, preferably using a jointed rod 29. The rod 29 is not removed through notch l02a until the hanger member is again raised and latched. Obviously, when the hanger member is raised, the latch head 16 is in registration with the slot 15b. After the head passes above plate 15a, the head 16 is turned through a ninety-degree angle so as to lie with its longer dimension crossing the longer dimension of slot 15b so as to firmly hold the lowering hanger member latched to the upper fixed member. A pin 15c limits this movement.

Means is provided for properly registering the lower member with respect to the upper member prior to the engagement of the electrical contacts 14, 91 and prior to the operation of the latching parts. This means differs slightly from that described in connection with the first modification. At opposite ends of the frame 17 at right angles to the frame member Ha are fixed the straps I06, which, as best seen in Fig. 13, have the inclined portions I060. which engage the lower edges He of the upper trough fixture H so as to guide the hanger member laterally into proper position to enter into the side portion of the upper fixture between the flanges 'Hd. Endwise alinement is provided by means of straps I01 positioned at opposite ends of the frame 11. The lower end of each strap I0! is fixed to plate 18, and the upper end of each of these straps is secured to the strap I06. Each of these end straps has an inclined portion 101a sloping upwardly and inwardly and adapted to engage a pin [08 extending across the end of the trough-like member H and connected between the flanges lid as best seen in Fig. 13. Thus the lower member is guided endwise so that all of the parts properly enter into the upper trough and so that the electrical contacts and latching parts are in registration.

What we claim is:

1. Lighting apparatus comprising a relatively fixed member in an elevated position and a lowering hanger member adapted to occupy a raised position adjacent and latched to said fixed member or to be unlatched and lowered therebelow, there being mating electrical contacts on said members engaged when said members are latched together, lamp means on said hanger member electrically connected with its associated electrical contacts, flexible supports connected between said members, equally spaced on each side of the center thereof adapted to hold said hanger member horizontal, spring counterbalance means on one of said members and connected with each of said flexible supports to wind up and pay out the supports as said hanger member is respectively raised and lowered, a positive latch individual to a pair of said coacting fixed and lowering members for latching said lowering member to said fixed member and positioned centrally of said members, an operator for said latch having a bayonet joint connection opening downwardly and adapted to receive a mating rod held by a person on the floor beneath said lighting apparatus, and said latch and operator being independent of said flexible supports.

2. The combination of claim 1 including a plurality of said mating contacts on one of said members, and a support for said plural contacts including pressure equalizing means for providing substantially equal pressure between mating contacts when said members are latched together.

3. The combination of claim 1 including a pair of said flexible supports on each side of the center of said hanger member, and each said pair being spaced on a line generally at right angles to a longitudinally extending center-line of said hanger member, whereby to stabilize and register said hanger member with said fixed member as said members approach latched position.

TI-IAYER B. FARRING'ION. WADE T. KELLER. HAROLD L. DALZELL.

REFERENCES CITED The following references are of record in the file of this patent:

Darley Apr. 20, 1948- 

